hey there,
all syncros have the same basic drive line, engines ect ( other than the euro diesel models which Aus. didn't get), the options are diff locks, power steering different trim levels eg. caravelle or transporter. Rear diff locks are quite common and are a disirable option as it makes up for lack of suspension articulation, front diff locks are virtually unheard of in australia and only a few came with this option.
As mentioned some of the trans. parts are expensive. With some smart shopping those costs can be reduced considerably,stay away from VW dealerships and shop on line where there are a few dedicated suppliers that offer alot of support to the syncro community.
100,000 k's is as good as they get these days and should give good service to around 180,000 k,s when trans + head gasket probs could start to appear, mines done 240,000k's and the heads are just starting to weep the gear box had its 3-4 slider hub replaced at 187,000k's.
The viscous coupling that acts as the center diff has been as source of great debate as it can and does harden over time causing added stress to the trans. and can cause major problems eg. total destrction if left unchecked.
Check out
http://www.syncro.org/ for all the info and links you should need to buff up on syncro stuff.
I've had mine for about three year and drive it every day its been totaly reliable and awsome fun to drive on and off road. learn what to look out for and you shouldn't have too many problems.
